May 2017

The Diabetes Control and Complications Trial (DCCT) demonstrated the beneficial effects of intensive versus conventional therapy on the development and progression of microvascular complications of type 1 diabetes. These beneficial effects were almost completely explained by the difference between groups in the levels of HbA1c, which in turn were associated with the risk of these complications. This study assessed the association of glucose variability with the development and progression of retinopathy, nephropathy, and cardiovascular autonomic neuropathy. It found that glycemic variability did not play an apparent role in the development of microvascular complications beyond the influence of the mean glucose.http://care.diabetesjournals.org/content/early/2017/03/28/dc16-2426

This study examined the effect of nocturnal and daytime clinical hypoglycemia on electrocardiogram (ECG) in young people with type 1 diabetes. Thirty-seven individuals with type 1 diabetes underwent 96 hours of simultaneous ambulatory ECG and blinded continuous interstitial glucose monitoring (CGM) while symptomatic hypoglycemia was recorded. Frequency of arrhythmias, heart rate variability was measured during hypoglycemia and normal glucose levels, during night and day. It discovered that asymptomatic hypoglycemia was common. It also identified differences in arrhythmic risk during nocturnal versus daytime hypoglycemia. The authors posit that their data provided further evidence that hypoglycemia predisposes to arrhythmia.http://care.diabetesjournals.org/content/40/5/655

This American study set out to develop a rational screening frequency for retinopathy. The models that were compared included recognized risk factors for progression of retinopathy. It reported that the probability of progression to proliferative diabetic retinopathy or clinically significant macular edema was limited to approximately 5% between retinal screening examinations at 4 years among patients who had no retinopathy, 3 years among those with mild retinopathy, 6 months among those with moderate retinopathy, and 3 months among those with severe non-proliferative diabetic retinopathy. The risk of progression was also closely related to mean glycated hemoglobin levels. The authors assert that over a 20-year period, the frequency of eye examinations was 58% lower with their practical, evidence-based schedule (based on a patient’s current state of retinopathy and glycated hemoglobin) than with routine annual examinations, which resulted in substantial cost savings.http://www.nejm.org/doi/full/10.1056/NEJMoa1612836

This open access paper opens with the statement that ischemia is the single most important predictor of future hard cardiac events, and that ischemia correction remains the cornerstone of current revascularization strategies. However, recent data suggests that, in diabetes (DM) patients, coronary atherosclerosis despite the absence of ischemia may not be associated with the same low risk of future cardiac events as seen in non-DM patients. This review examined the current evidence supporting an ischemia driven revascularization strategy, and challenged the notion that ischemia is the only clinically relevant factor in the prediction of cardiovascular outcomes in DM patients. Specifically, they examined whether in DM patients certain characteristics beyond ischemia, such as microvascular disease, coronary atherosclerosis burden, progression and plaque composition, may need to be considered for a more refined risk stratification in these high-risk patients. The conclusions were that DM patients have more rapidly progressive coronary atherosclerosis, a higher degree of microvascular disease, a larger burden of coronary plaque and a significantly different composition of atherosclerosis compared to non-DM patients. The authors warn that this finding should force a rethink the strategy for dealing with coronary atherosclerosis in DM patients. They assert that ischemia is only one, but clearly not the only factor to take into account. https://cardiab.biomedcentral.com/articles/10.1186/s12933-017-0533-7

This study looked at patients registered in the Swedish National Diabetes Register from 1998 through 2012 and followed them through 2014. Trends in deaths and cardiovascular events were estimated, alongside controls who were matched for age, sex, and county and randomly selected from the general population. The findings were that mortality and the incidence of cardiovascular outcomes declined substantially among persons with diabetes, although fatal outcomes declined less among those with type 2 diabetes than among controls.http://www.nejm.org/doi/full/10.1056/NEJMoa1608664

This study looked at cases of type 1 and type 2 diabetes mellitus at five study centers in the United States. A total of 11,245 youths with type 1 diabetes (0 to 19 years of age) and 2,846 with type 2 diabetes (10 to 19 years of age) were identified. It found that overall incidence rates of type 1 diabetes increased by 1.4% annually (from 19.5 cases per 100,000 youths per year in 2002–2003 to 21.7 cases per 100,000 youths per year in 2011–2012). Overall rates of type 2 diabetes increased by 7.1% annually (from 9.0 cases per 100,000 youths per year in 2002–2003 to 12.5 cases per 100,000 youths per year in 2011–2012). The report also highlighted that the incidence increased significantly among youths of minority racial and ethnic groups.http://www.nejm.org/doi/full/10.1056/NEJMoa1610187

The purpose of this study was to assess the impact of frequency and tone of parent – youth communication on glycemic control. The authors note that adolescence provides a unique set of diabetes management challenges, including suboptimal glycemic control, and that continued parental involvement in diabetes management is associated with improved HbA1c outcomes. However, they also note that diabetes-related conflict within the family can have adverse effects. The specific impact of frequency and tone of such communication is largely understudied. The study recruited a total of 110 youths with type 1 diabetes, and their parents completed questionnaires assessing diabetes-related adherence, family conflict, and family communication (i.e., frequency and tone) during a routine clinic visit. Routine testing of HbA1c was performed. Interestingly, the findings were that youth- and parent-reported frequency of communication were unrelated to HbA1c. Instead, greater discrepancies between parents and children on reported frequency of communication (most commonly parents reporting frequent and youth reporting less frequent communication) corresponded with poorer glycemic control and increased family conflict. Also, a more positive tone of communication as rated by youth was associated with lower HbA1c. Unsurprising the conclusion of this study was that diabetes-related communication is more complex than conveyed simply by how often children and their parents communicate. https://rd.springer.com/article/10.1007%2Fs13300-017-0259-2

This study examined sixteen Norfolk general practices, representing a population of 24,661 older people, including 3,862 (15.7%) with Type 2 diabetes. Of these, 1,379 (35.7%) people were prescribed sulfonylurea or insulin therapies. Data extracted included age, sex, last recorded HbA1c value, renal function, and dementia codes. The median age of the study cohort was 78 years. A total of 644 people (47.8%) had chronic kidney disease and 60 people (4.35%) had dementia. The average HbA1c concentration for the entire cohort was 58 (51–69) mmol/mol [7.5 (6.8–8.5)%], with no difference in median HbA1c between those with or without either chronic kidney disease or dementia. Stratified by prescription for sulfonylurea, insulin, or combined insulin and sulfonylurea therapies, 282 (35.2%), 93 (24.2%) and 25 people (16.3%), respectively, had HbA1c < 53 mmol/mol (7.0%). Treatment to an HbA1c target of < 53 mmol/mol (7.0%) was as prevalent in those with chronic kidney disease or dementia as in those without. The authors concluded that in the present cohort of older people with Type 2 diabetes prescribed sulfonylurea or insulin therapies, overtreatment was common, even in the presence of comorbidities known to increase hypoglycaemia risk.http://onlinelibrary.wiley.com/doi/10.1111/dme.13380/abstract

The impact of continuous glucose monitoring on markers of quality of life in adults with type 1 diabetes
William H. Polonsky et al. Diabetes Care. DOI: https://doi.org/10.2337/dc17-0133

Although continuous glucose monitoring (CGM) improves glycemic control, data are inconclusive about its influence on quality of life (QOL). The investigators looked at the impact of 24 weeks of CGM use on QOL in adults with type 1 diabetes (T1D) who use multiple daily insulin injections. It looked at the results from DIAMOND, a prospective randomized trial that assessed CGM versus self-monitoring of blood glucose (SMBG) in 158 adults with poorly controlled T1D. It found that the CGM group demonstrated a greater increase in hypoglycemic confidence and a greater decrease in diabetes distress than the SMBG group. However, no significant group differences in well-being, health status, or hypoglycemic fear were observed. In particular, CGM satisfaction was not significantly associated with glycemic changes but was associated with reductions in diabetes distress and hypoglycemic fear and increases in hypoglycemic confidence and well-being. To summarise: CGM contributes to significant improvement in diabetes-specific QOL (i.e., diabetes distress, hypoglycemic confidence) in adults with T1D, but not with QOL measures not specific to diabetes (i.e., well-being, health status). CGM satisfaction was associated with most of the QOL outcomes but not with glycemic outcomes.http://care.diabetesjournals.org/content/early/2017/04/03/dc17-0133